<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script src="../vue.js"></script>
</head>

<body>
    <div id="app">
        <h1>全名:{{fullName}}</h1>
    </div>
    <script>
        Vue.config.productionTip = false;
        /* 
            使用watch来书写获取全名的逻辑,感受watch和computed的区别
        */
        const vm = new Vue({
            el: "#app",
            data() {
                return {
                    firstName:"wang",
                    lastName:"zhongwang",
                    fullName:"",
                };
            },
            watch:{
                firstName:{
                    immediate:true,
                    handler(){
                        this.fullName = this.firstName.toLowerCase() +  " " + this.lastName.toLowerCase();
                    },
                },
                lastName:{
                    immediate: true,
                    handler(){
                        this.fullName = this.firstName.toLowerCase() +  " " + this.lastName.toLowerCase();

                    }
                }
            }
        })
</script>
</body>

</html>